Polycraft Dirt Houses
Figure 1 shows one possible footprint of a dirt house that can lead to a valid Housing structure that can support a Technology Level 1 population. The maximum outer footprint of a dirt house is 5 x 5, while the inner footprint is 3 x 3. This doesn't leave too much room for creativity in your civic engineering, now does it? Well, your design freedom will explode as your houses get bigger and taller and are made from better materials. Your population density will also increase.
Figure 2 shows a side view of a valid dirt house with a decent amenity score leading to a single happy Villager. Notice the windows, paintings, flowers and light level all factor into the Happiness score for that Villager. Also note that 85% of the structure is made of dirt. Too many windows leads to a structure that cannot house Polycraft World Refugees. Also beware of the mechanics around the door. Housing must use wooden doors. The doors must have a solid block frame (no glass around the frame). The door must also have an entry way that is empty. No torches on the first block inside your Housing structure. The entry block (or the ceiling block of the coordinate just inside the door must also be solid.